A dosage form for intranasal and/or inhalation administration of an analgesic having low opioid receptor binding activity to a warm blooded animal, that includes a pharmaceutically effective amount of the analgesic. A preferred analgesic is tramadol, a tramadol and/or a pharmaceutically acceptable salt, metabolite or derivative thereof. Methods of making and using the formulation according to the invention are also provided.

The present invention relates to formulations and methods for the intranasal and inhalation administration of analgesics having low opioid receptor binding affinity.
Pharmacologically active compounds are most commonly administered by the oral route. In particular, analgesics are preferably taken by mouth. However, this convenient route of administration is not always possible for certain patients. Contraindications to oral administration of analgesics can include nausea and/or emesis, oral or gastrointestinal surgery and dysphagia. In addition, rate of analgesia onset is slower and more variable due to first pass effects which compromise the apparent potency of some analgesics and complicate their use. The alternative of administration by injection, e.g., parenteral, intramuscular or subcutaneous injection, is generally not preferred due to patient discomfort and the attendant increased costs associated with the production of and administration of injectable products.
Another, less invasive form of administration is transmucosal administration. Transmucosal administration can be via oral, nasal and/or upper respiratory tract, rectal or vaginal mucosal surfaces, to name the more common non-oral transmucosal routes of administration. Transmucosal administration has the advantage that patients who are unable to swallow can be medicated without recourse to injection. Importantly, transmucosal administration may often provide a more rapid relief of pain, compared to oral administration, by providing direct access to the blood circulation and bypassing the gastrointestinal tract and portal vein circulation and liver metabolism.
A particularly preferred route for transmucosal delivery is intranasal administration for absorption by the nasal mucosal surfaces and/or inhalation for absorption in the bronchial passages of the lungs.
Heretofore, it has been taught that only certain opioid analgesic compounds would be suitable for intranasal transmucosal administration. For example, given the difficulties of delivering compounds across the mucosal barrier and the limited mucosal area that is conveniently available to intranasal administration, only the most potent opioid analgesics, antagonists or mixed agonist/antagonist drugs were taught to be candidates for intranasal delivery. In addition, only those opioid compounds for which oral delivery was variable and problematic were generally considered for intranasal delivery.
For example, U.S. Pat. No. 4,464,378, by Hussain (1984), discloses the intranasal transmucosal administration of certain potent narcotic agonists, antagonists and mixed agonist/antagonists. The Hussain disclosure relates to two classes of compounds, morphine and certain of its structurally close relatives and xcex949-tetrahydrocannabinol (xe2x80x9cdelta-9-THCxe2x80x9d). The opioid compounds disclosed to be intranasally effective by Hussain are morphine-like compounds retaining a phenolic group, that are also of high potency (typically exhibiting high mu receptor potency, whether agonist, antagonist or mixed agonist/antagonist) and are stated to be rarely used orally because of inefficient and variable absorption by that route. However, Hussain does not teach the intranasal administration of analgesics that are either weak opioids or non-opioid analgesics, which are also well absorbed orally with predictable efficacy.
Wenig et al., U.S. Pat. No. 4,778,810, issued in 1988, discloses the administration of caffeine by nasal administration. Caffeine is a xanthine derivative completely unrelated to the opioids and unrelated to the non-opioid analgesics.
Frost, U.S. Pat. No. 4,880,813, issued in 1989, discloses a method of treatment of allergic rhinitis by the intranasal administration of the narcotic antagonist nalmefene. Nalmefene, (6-methylene-6-desoxy-N-cyclopropylmethyl-14-dihydronomorphine) is a pure opioid antagonist with a prolonged duration of action. Frost states that Nalmefene is believed to act locally on nasal tissues by inhibiting mast cell degranulation provoked by endogenous opioids acting on receptors in the nasal mucosa and the upper respiratory tract. Thus, Frost does not disclose or suggest any systemic delivery of malmefene or any other opioid compound into the blood circulation.
Cohen, U.S. Pat. No. 4,973,596, issued in 1990, discloses a method of intranasally administering the synthetic narcotic analgesic, meperidine, which is a synthetic opioid drug, in a suitable dosage form. However, the effectiveness of intranasal and/or inhalation administration of a weak opioid or non-opioid analgesic is unpredictable from the disclosures of the intranasal effectiveness of morphine or its derivatives, or meperidine, which are conventional strong opioid receptor binding agents. Therefore, the art does not disclose that a weak opioid receptor binding compound, such as the analgesic tramadol, or its derivatives and pharmaceutically acceptable salts, can be delivered by transmucosal and/or inhalation administration.
Tramadol, which has the chemical name (xc2x1) trans-2-[(dimethylamino)methyl]-1-(3-methoxyphenyl) cyclohexanol, is an orally active opioid analgesic. Conventional release preparations in the form of capsules, drops, suppositories and formulations for systemic injection, containing tramadol, or more particularly its hydrochloride salt, have been commercially available for many years for use in the treatment of moderate to severe pain (e.g., ZYDOL, by Searle; more recently ULTRAM, by Ortho-McNeil Pharmaceutical). Tramadol hydrochloride is currently administered in single oral doses of 50, 75, 100, 150 and 200 mg to patients with, e.g., postoperative pain. In addition, controlled release preparations for oral administration of tramadol are disclosed by co-owned application, U.S. Ser. No. 08/241,129, filed on May 10, 1994, the disclosure of which is incorporated herein by reference.
Tramadol is a centrally acting synthetic analgesic compound. Unlike conventional opioids, the mechanism of action of tramadol is not completely understood. However, it is known that tramadol binds opioid receptors at low affinity and that the tramadol metabolite mono-O-desmethyltramadol (denoted xe2x80x9cM1xe2x80x9d) binds to opioid receptors at high affinity. The M1 metabolite exhibits substantially greater analgesic activity in animal models than does tramadol. It is also known that tramadol antagonizes reuptake of both norepinephrine and serotonin (in vitro), which may also contribute to the analgesic action of tramadol. In animal models, M1 is up to 6 times more potent than tramadol in producing analgesia and 200 times more potent in opioid receptor binding. However, the contribution to human analgesia of tramadol relative to tramadol metabolite M1 is unknown. The unconventional nature of tramadol-induced antinociception is confirmed by reports that the opioid antagonist naloxone only partially antagonizes tramadol-induced antinociception in animal models. Thus, tramadol exhibits both a unique chemical structure and mechanism of action relative to conventional opioids.
Heretofore there has been no acceptable method or formulation for the transmucosal administration of tramadol, an analgesic which is believed to provide analgesic activity by either or both opioid and non-opioid mechanisms, which is readily absorbed by the oral route and which is not of the highest opioid receptor binding.
It is accordingly an object of the present invention to provide a pharmaceutical dosage form of an opioid that binds weakly to opioid receptors that can be administered intranasally and/or by inhalation.
Another object of the present invention is to provide a pharmaceutically acceptable dosage form of tramadol that can be administered intranasally and/or by inhalation.
Still another object of the present invention is to provide a method of treating a patient with a pharmaceutically acceptable dosage form of tramadol or its derivatives or pharmaceutically acceptable salts via intranasal and/or inhalation administration.
In accordance with the above objects and others which will be apparent from the further reading of the specification and of the appended claims, the present invention is related to the surprising discovery that an analgesic that is a weak opioid receptor binding compound can be effectively administered to a warm blooded animal, including a human patient, by administering a pharmaceutically effective amount of the compound, or a pharmaceutically acceptable salt, to the respiratory tract mucosal surfaces of an animal in need of treatment.
The invention also provides for a dosage form for intranasal and/or inhalation administration of a weak opioid or non-opioid analgesic, to a warm blooded animal.
The invention also provides for a method for producing analgesia in a warm blooded animal, such as a human patient, comprising contacting respiratory tract mucosal surfaces, such as the nasal and/or bronchial mucosal surfaces of a warm blooded animal in need of analgesia, with an analgesically effective amount of a weak opioid or non-opioid analgesic.
The compound can be, for example, the weak opioid analgesic tramadol, either as the free base, and/or as its pharmaceutically acceptable derivatives, salts and active metabolites or in any combination thereof. The compound can be administered to the respiratory tract either intranasally and/or by inhalation.
The dosage form can include a pharmaceutically effective amount of a weak opioid or non-opioid analgesic, such as, e.g., tramadol as described above, together with a pharmaceutically acceptable carrier that is suitable for intranasal and/or inhalation administration. The dosage form can contain, for example, tramadol HCl in an amount ranging from 10 mg to 500 mg.
The dosage form suitable for intranasal and/or inhalation administration can be in the form of, e.g., a liquid solution, suspension, emulsion, liposome or similar such multiphasic composition. Preferably, the dosage form includes a carrier of isotonic saline and a pharmaceutically acceptable buffer. For intranasal administration alone, the dosage form may also include an emulsion, a paste, a cream and/or a gel or gauze packing impregnated with the analgesic to be administered. A useful tramadol metabolite, that is also analgesically active, is for example, mono-O-desmethyltramadol, which can also be so administered at an effective dose intranasally and/or by inhalation alone or in combination with another drug, such as, for example, a tramadol and/or a salt or derivative thereof.
Accordingly, the present invention provides compositions and methods having utility for the administration, via the respiratory tract, of analgesic drugs having low opioid receptor binding activity. Preferably, the analgesic drugs include the analgesic drug tramadol and derivatives and salts thereof. Reference to xe2x80x9ctramadolxe2x80x9d herein, unless indicated otherwise, is also understood to encompass all pharmaceutically acceptable forms of tramadol, either as the free base and/or as its pharmaceutically acceptable derivatives, salts and active metabolite and/or combinations thereof, all of which are contemplated to be used in the present compositions and methods. Reference to the term xe2x80x9csaltxe2x80x9d herein, i.e., tramadol salt, is also intended to encompass the haloacids, i.e., tramadol HCl and the like, unless otherwise indicated.
In accordance with the present invention, an effective amount of a pharmaceutically acceptable form of tramadol is administered intranasally, e.g., by contact with mucosal surfaces in the nasal passages.
Pharmaceutically acceptable carriers for administering tramadol to the nasal mucosal surfaces will be readily appreciated by the ordinary artisan. Such carriers are disclosed, simply by way of example, by Remington""s Pharmaceutical Sciencesxe2x80x9d 16th edition, 1980, Ed. By Arthur Osol, the disclosure of which is incorporated by reference herein in its entirety.
The selection of appropriate carriers depends upon the particular type of administration that is contemplated. For administration via the upper respiratory tract, e.g., the nasal mucosal surfaces, tramadol can be formulated into a solution, e.g., water or isotonic saline, buffered or unbuffered, or as a suspension, for intranasal administration as drops or as a spray. Preferably, such solutions or suspensions are isotonic relative to nasal secretions and of about the same pH, ranging e.g., from about pH 4.0 to about pH 7.4 or, from pH 6.0 to pH 7.0. Buffers should be physiologically compatible and include, simply by way of example, phosphate buffers. For example, a representative nasal decongestant is described as being buffered to a pH of about 6.2 (Remington""s, Id. at page 1445). Of course, the ordinary artisan can readily determine a suitable saline content and pH for an innocuous aqueous carrier for nasal and/or upper respiratory administration.
Tramadol containing intranasal carriers include nasal gels, creams, pastes or ointments with a viscosity of, e.g., from about 10 to about 3000 cps, or from about 2500 to 6500 cps, or greater, may also be used to provide a more sustained contact with the nasal mucosal surfaces. Such carrier viscous formulations may be based upon, simply by way of example, alkylcelluloses and/or other biocompatible carriers of high viscosity well known to the art (see e.g., Remington""s, cited supra. A preferred alkylcellulose is, e.g., methylcellulose in a concentration ranging from about 5 to about 1000 or more mg per 100 ml of carrier. A more preferred concentration of methyl cellulose is, simply by way of example, from about 25 to about mg per 100 ml of carrier. The carrier containing the drug can be soaked into a fabric material, such as gauze, that can be applied to the nasal mucosal surfaces to allow for drug penetration therein.
Other ingredients, such as art known preservatives, colorants, lubricating or viscous mineral or vegetable oils, perfumes, natural or synthetic plant extracts such as aromatic oils, and humectants and viscosity enhancers such as, e.g., glycerol, can also be included to provide additional viscosity, moisture retention and a pleasant texture and odor for the formulation. For nasal administration of solutions or suspensions according to the invention, various devices are available in the art for the generation of drops, droplets and sprays. For example, tramadol solutions can be administered into the nasal passages by means of a simple dropper (or pipet) that includes a glass, plastic or metal dispensing tube from which the contents are expelled drop by drop by means of air pressure provided by a manually powered pump, e.g., a flexible rubber bulb, attached to one end. Fine droplets and sprays can be provided by a manual or electrically powered intranasal pump dispenser or squeeze bottle as well known to the art, e.g., that is designed to blow a mixture of air and fine droplets into the nasal passages.
The tear secretions of the eye drain from the orbit into the nasal passages, thus, if desirable, a suitable pharmaceutically acceptable ophthalmic solution can be readily provided by the ordinary artisan as a carrier for the analgesic compounds to be delivered and the analgesic can be administered to the orbit of the eye in the form of eye drops to provide for both ophthalmic and intranasal administration.
In one embodiment, a premeasured unit dosage dispenser that includes a dropper or spray device containing a solution or suspension for delivery as drops or as a spray is prepared containing one or more doses of the drug to be administered. The invention also includes a kit containing one or more unit dehydrated doses of tramadol, together with any required salts and/or buffer agents, preservatives, colorants and the like, ready for preparation of a solution or suspension by the addition of a suitable amount of water. The water may be sterile or nonsterile, although sterile water is generally preferred.
For administration by inhalation into the lower respiratory tract, e.g., the bronchioles, by inhalation, tramadol can be formulated into a solution and/or a suspension of particles in a carrier appropriate for inhalation. Such carriers are also well known to the ordinary artisan familiar with inhalants for the delivery of fine droplets and insufflations for the delivery of inhalable fine particles, on the order of, for example, from about 0.5 to 1 micron, and preferably from about 0.5 to about 0.7 micron, comprised of powders, mists or aerosols, into the respiratory tract (Remington""s, Id., at page 1451).
For inhalation of droplets, mists and aerosols various devices such as nebulizers or pressurized aerosol generators are readily available. In addition, such devices can be metered to provide uniformity of dosing (Remington""s, Id.).
Dry powder inhalers of types readily disclosed in the art may also be used, as well as micronized shavings of isostatically compressed tablets or discs of drug with or without inert binders such as lactose may be used.
All inhalers may be designed and fashioned to deliver liquid or solid particles to the nasal mucosa as well as the upper and/or lower airways.
In one embodiment, drugs for nasal and/or inhalation administration can be administered as powders. The powdered drug or composition is normally located within a container such as a hard gelatin capsule or a blister package, or a multi-dose devise. The capsule or blister is ruptured or broached within in an inhaler device, thereby enabling the powder to be inhaled. Generally, the mean particle size of the drug used for inhalation is between 1 and 10 micron with the size range between 2 and 5 microns being particularly suitable for penetrating the peripheral airways of the lungs. Such particle size ranges are commonly achieved by micronisation or spray drying.
The finely divided drug powder is often administered as a composition comprising a blend or mixture of the medicament with an inert carrier. Usually the inert carrier has a mean particle size substantially larger than that of the drug. This provides, among other advantages, an improvement in the flow properties and dispensing accuracy of the composition.
Commonly described carrier materials for produced drug, include calcium carbonate and sugars, for example sucrose, mannitol or dextrose or, more particularly, lactose, which are pharmaceutically acceptable and pose no problems of toxicity, since any residues imbibed during dosing are well tolerated upon digestion or may be easily eliminated by disillusion (e.g., in the case of the sugars) or mucocilliary clearance from the lung.
The composition in the capsule or blister is frequently about 25 mgs. This weight probably represents the maximum quantity of powder that may be comfortably inhaled without undue side effects, such as coughing, and also corresponds to the minimum quantity that is usually dispensed by filling machines.
Preferred compositions according to the invention, are those in which the carrier has a particle size distribution in which at least 7% by weight of the carrier particles are at or below about 11 microns, and at least about 20% by weight are at or below about 33 microns, and at least about 20% are at or above 63 microns. Furthermore, particularly those in which the carrier has particle size distribution in which 8% by weight of the carrier particles are at or below 11 microns, and at least 35% by weight are below 33 microns, at least 25% by weight are above 63 microns, especially those in which the carrier has a particle size distribution in which at least 9% by weight are at or below 11 microns, and at least 25% by weight are below 33 microns, and at least 35% by weight are above 63 microns.
Particle sizes referred to in this specification are measured by laser diffraction on a Malvern Instruments Particle Sizer.
Preferred compositions according to the invention for powder inhalation, are those in which the carrier is present at a concentration of about 95.0 to 99.99%. More particularly, from 97.0 to 99.9%, especially from 98.0 to 99.8%, by weight. Processes for preparing such powders, by the application or adaptation of known methods, also constitute features of the invention.
Thus, according to a feature of the invention, a pharmaceutically acceptable solid carrier, preferably in a fluidized bed, is sprayed with a solution of an anti-static additive in a suitable solvent, e.g. ethanol, followed by drying, preferably in a fluidized bed, followed by blending with micro fine solid pharmaceutically active compound or followed by blending with a mixture of a micro fine solid pharmaceutically active compound with a finely divided pharmaceutically acceptable solid carrier.
Anti-static agents suitable for this purpose include those disclosed by Simpkin et al. in International Application WO 94/04133 published March 1994, the disclosure of which is incorporated by reference herein in its entirety.
For powder delivery of analgesic medicament, the medicament, e.g., tramadol, is preferably present in the compositions of the invention at a concentration of about 0.01% to 5.0%. More particularly, from 0.1% to 3.0%, especially from 2.0% by weight.
In general, insufflation inhalation devices suitable for use in connection with the particulate dosage forms of the invention comprise a housing having a passageway for the flow of air, in which one end of the passageway is designed for insertion in the mouth or nose, a chamber containing controlled release particles of a cohesive agglomerate of a medicament together with a pharmaceutically acceptable carrier suitable for oral inhalation, wherein the average discrete particle size is from about 0.1 to about 10 microns in diameter for the oro-pulmonary route or 10 to 355 xcexcm for the nasal route, actuating means for releasing a unit dose of said particles into said passageway, such that the unit dose is drawn through said passageway during an inspiration by the patient and is delivered to the naso-pharynx and/or the pulmonary tract of the patient.
The formulations of the present invention may be adapted for use with respect to any oral and/or nasal insufflation device for powdered or solid medicaments. For example, the powder of the present invention may be compressed into a solid dosage form such as a ring tablet which is then placed into an appropriate insufflation device which includes comminuting or other means for providing discrete powder particles in the respirable fraction from the insufflation device when the device is actuated (e.g., when a unit dose of medicament is to administered via inspiration).
There are many devices described in the prior art which are useful for delivering a dose of powdered drug to the respiratory tract or naso-pharynx of a patient. Examples of such devices which would be useful in delivering the formulations of the present invention are described below.
One such device is known as the Bespak device described in International patent application WO 92/00771 (published on Jan. 23, 1992 claiming priority from Great Britain Patent Application No. 9015522.7 filed on Jul. 13, 1990; assigned to Innovata Biomed Limited.), hereby incorporated by reference. The device described therein includes a storage chamber for storing a powdered drug to be administered and a metering member having metering cups in which individual doses of the powdered drug are placed. Air is inhaled through an inhalation passage at one end of the device and directed into contact with the metering cup that has been filled with the powdered drug. The metering cup is oriented upwardly open to face the air stream and to enable the powder to be released from the cup. Upon inhalation, the dose is mixed with the air flow and continues through the mouthpiece to be inhaled.
The metering cups on the metering member are arranged on an outer frusto-conical wall so that each metering cup is position able to be upwardly open and face the air flow during inhalation. The metering member rotates so that the metering cups move between a position in which the cup receives a dose of the powered drug from the storage chamber to a position in which the cup is exposed to the air flow. As one cup is exposed to the air flow, another cup is aligned with the storage chamber and is being filled with powder.
After the dose is blown from the metering cup, and upon subsequent rotation of the metering member, the cup is wiped and cleaned by a wiping element to remove any undispersed powder and then dried via a moisture absorbent material.
Another device for delivery of inhalation powders is described in U.S. Pat. No. 2,587,215 (Priestly), hereby incorporated by reference. Priestly describes an inhaler having a storage chamber containing a powdered medicament, a mixing chamber and means to move a set dose of medicament from the storage chamber to the mixing chamber. The dose is mixed with air in the mixing chamber and inhaled through a mouthpiece.
Yet another inhalation device suitable for delivering powdered inhalation drugs is described in U.S. Pat. No. 4,274,403 (Struve), hereby incorporated by reference. Struve describes an inhaler for administering a powdered drug nasally, which includes storage means for containing a quantity of the drug therein. The storage means includes a feed hole through which the powdered drug may be received from the storage means. The device further includes a dispensing head operatively coupled to the storage means for dispensing the powdered drug more nasally. The dispensing head of the Struve inhaler includes a nozzle, a body portion, a dispensing cylinder and a vent means. The nozzle is shaped to be received in the nasal passage of the user. The nozzle includes a dispensing passageway for dispensing the dose into the nasal cavity of patient.
The body portion is located adjacent the nozzle and has a traverse bore therein. The traverse bore operatively connects the dispensing passageway in the nozzle with the feed hole leading to the drug storage means. The feed hole and the dispensing passageway are transversely offset relative to one another at the points where they enter the transverse bore.
The dispensing cylinder includes a metering chamber. The metering chamber may be selectively aligned with either the feed hole or the dispensing passageway. The dispensing cylinder is slidably received in the transverse bore for movement between a first transverse position in which the metering chamber is aligned with the feed hole and a second transverse position in which the metering chamber is aligned with the dispensing passageway. In its first position, the metering chamber can be filled with a charge of the powdered drug when the inhaler is manipulated. In the second position, places the charge of the powdered drug into the dispensing passageway for inhalation by the user.
The vent means is formed as part of the dispensing cylinder and is capable of venting the metering chamber to atmosphere only in the second position of the cylinder, i.e. when the powder disposed in the device such that it may be inhaled by the user.
Another inhaler device is disclosed in U.S. Pat. No. 4,524,769 (Wetterlin), hereby incorporated by reference. Wetterlin describes a dosage inhaler for administering a micronized pharmacologically active substance to a patient. The inhaler includes a gas conduit means through which gas passes for carrying the micronized substance to be administered. The inhaler further includes a membrane having a plurality of preselected perforated portions, each portion adapted to hold and dispense a reproducible unit dose of less than 50 mg of said active substance, in dry powder form. The powder particles have a particle size of less than 5 micrometers. The membrane is movably connected to the gas conduit means so that one of the preselected portions can be positioned within the gas conduit means so that the substance held in the preselected portion may be dispensed. The remaining preselected portion can be in a position external to said gas conduit means to receive said active substance. The membrane is movable through a plurality of positions whereby each preselected portion of the membrane can be successively positioned within the gas conduit to dispense the unit dose of the active substance held therein. Each preselected portion from which the active substance has been dispensed can be moved to said external position to receive active substance.
GB Patent Application No. 2,041,763, hereby incorporated by reference, describes an inhaler having a powder storage chamber and a rotatable metering member having dosing holes which open to the storage chamber in one position and open to the mixing chamber in another position. Upon rotation of the metering member, the powder is carried from the storage chamber to the mixing chamber to be inhaled.
EP 0 079 478, hereby incorporated by reference, describes an inhaler having a storage chamber, inhalation air passage and rotatable delivery member having a cavity formed therein. The delivery member is rotated from one position in which the cavity receives powder from the storage chamber to another position in which the powder falls from the cavity by the effect of gravity into a collector positioned in the air passage.
U.S. Pat. No. 4,860,740 (Kirk et al.), hereby incorporated by reference, describes an inhaler having a rotatable metering member with recesses formed therein. The recesses contain a powdered medicament. Upon rotation of the metering member, one of the recesses in exposed to the air inhalation passage to be entrained in the air stream and inhaled.
The Easyhaler, described in PCT publication WO 92/09322, hereby incorporated by reference in its entirety, is a device that includes a supply of a pulverized medical substance and a xe2x80x9cdosing meansxe2x80x9d, which is a rotatable cylinder having five uniform recesses arranged around the periphery of the cylinder. The cylinder is rotated such that one recess aligns with the supply of drug and is filled by a quantity of the drug while another recess aligns with an air channel connected to the mouthpiece. The filled recess is then rotated to another position in the direct path of an inhalation air flow. The dose is pre-set by the recessed portion of the rotatable dosing means and is flushed clean by the direct air flow through the inhalation chamber.
To operate the device, the rotating dosing means is turned so that a full dosing chamber (having already been filled up after the previous use) is rotated into alignment with the air channel leading to the mouthpiece. Upon inhalation by the user, air is drawn through apertures and nozzles directly into the dosing chamber. The air flow flushes the dosing chamber causing the drug to be carried with the air in the direction of the inhalation through the mouthpiece. The axis of the air channel is arranged at an angle to the axis of the dosing means of between 70xc2x0 and 110xc2x0, but preferably 90xc2x0 (perpendicular).
U.S. Pat. No. 5,176,132, hereby incorporated by reference, discloses a device for the administration to the lung by inhalation of a medicament in powdered form. The device includes a mouthpiece, a medicament reservoir communicating with said mouthpiece, and metering means for dispensing a dose of medicament from the reservoir. The reservoir contains a compacted body of powdered medicament including an active ingredient having a particle size of from 1 to 10 xcexcm when in loose powder form. The metering means includes a rotatable helical blade for abrading the compacted body. Thus when actuated, the helical blade abrades the compacted powdered medicament into particles capable of being inhaled into the respiratory tract of a patient.
International patent applications, PCT/EP93/01157 and PCT EP93/01158 (assigned to GGU), hereby incorporated by reference, which are directed to the device and to the ring tablet, respectively.
GGU""s device includes an active annular body (medicament reservoir) situated in a mouthpiece. The body forms the beginning of an inhalation tube through which the medicament is inhaled. The drug is in a compacted and annular form. In use, a face mill cutter is caused to rotate, thereby generating particles of the drug. Upon inhalation, air flows through air inlet openings in the casing and in the area of the cutting edges of the face mill cutter. Together with depressions situated between the cutting edges, the inlet openings and the depressions form an air channel leading to the mouthpiece, through which the drug particles are inhaled.
The quantity of each dose is determined by the amount of rotations of the face mill cutter. A spring presses the inhalation tube and thus the drug body toward the face mill cutter. In operation, a wind-up button is rotated to load the spring. By pressing the trigger mechanism, the spring is released thereby rotating the upper portion to which is connected the face mill cutter.
According to International patent application PCT/EP 93/01158, the supply of pharmaceutical agent is present in solid, homogenous tablet form and has an isotropic solid structure. The strength, density and composition of the solid is homogenous. The tablets are made via cold isostatic pressure (CIP) at pressures between 50-500 Megapascal(Mpa).
An effective dose of e.g., intranasal and/or inhaled tramadol is readily determined by the ordinary artisan by titration of the dose until sufficient analgesia is attained or by titrating serum levels of tramadol until serum levels known to be effective are attained. Generally, an effective intranasal and/or inhaled dose of tramadol HCl for an adult is in a range from about 10 to about 500 mg per dose or even from about 50 to about 250 mg per dose. A therapeutically effective serum level of, e.g., tramadol HCl, is reported to range from about 150 to 225 ng/ml of serum. The elimination half-life of tramadol is reported to range from 6 hours in adults to 7 hours in the very elderly (over 75 years). Plasma clearance rates of tramadol have been reported to be 6.4 ml/min/kg in males and 5.7 ml/min/kg in females following a 100 mg IV dose of tramadol. Following a single oral dose, and after adjusting for body weight, females are reported to have a 12% higher peak tramadol concentration and a 35% higher area under the concentration-time curve compared to males. Thus, for example, the artisan will appreciate that the effective dosages will be adjusted in proportion to age, body weight, metabolic activity and renal clearance.
Tramadol HCL is about 30% soluble in water (300 mg/ml). The formulation according to the invention is prepared to include tramadol in a concentration ranging from about 10 to about 300 mg/ml and more, preferably in a concentration ranging from about 150 to about 200 mg per ml. Thus, simply by way of example, the formulations according to the invention can be administered intranasally and/or by inhalation in a volume ranging from about 0.15 ml to about 1 ml or greater, depending on the desired dose. Dosage weights expressed for tramadol hydrochloride can also be readily expressed as equivalent amounts of other tramadol salts, derivatives or active metabolites that may be substituted therefore, in proportion to the relative potency of the other optional forms of tramadol compared to tramadol HCl. Of course, where increased solubility is obtained by supersaturation of the solution, modifications to the structure of tramadol or modifications to the salt or to the solute, the range of concentrations will be increased accordingly.
Derivatives of tramadol may also be used in the present invention. For example, since nasally administered tramadol avoids the direct enterohepatic circulation and the resulting metabolic conversion in the liver, it may be desirable to administer the metabolite mono-O-desmethyltramadol together with or instead of tramadol itself, in order to obtain the benefit of the analgesic activity of this metabolite. In particular, since mono-O-desmethyltramadol is about 6 times more potent than tramadol as an analgesic, the effective dose will be adjusted accordingly. Dosages of other tramadol salts or derivatives should be adjusted accordingly in proportion to potency relative to tramadol HCl.
The following examples, which are in no way intended to limit the scope of the present invention, illustrate the preparation of typical compositions and unit dosage forms suitable for nasal administration of tramadol.

Formulation for respiratory tract administration


A portable communication device includes an apparatus for environmental sensing. The apparatus includes a housing, one or more environmental sensors and an optical source. The housing includes one or more ports for allowing air flow between the surrounding environment and a cavity of the housing. The environmental sensors are coupled to the housing and can sense an environmental agent included in the air flow. The optical source can illuminate the cavity of the housing to decompose unwanted organic compounds inside the port.

Many mobile electronic devices are equipped with sensors and transducers that enable the devices to perform far more functionalities than communications. Media playing, photography, location detection, online shopping, social media, online banking, calendar and health applications such as heartbeat, blood pressure and blood oxygen level measurement are among the numerous applications that a smart mobile communication device can facilitate. Further, smart mobile communication devices (e.g., smartphones and smartwatches) can be equipped with environmental sensors, such as pressure sensors, humidity sensors and gas sensors.
Environmental sensors integrated into a mobile electronic device can offer novel features such as personal environmental detection and air quality monitoring. However, these devices are prone to organic residue accumulation, such as skin oils, dirt, body hair, etc. Such accumulations can contaminate the device housing and/or the sensor packaging that can produce interference signals and result in increasing sensor errors over an extended period of time. For example, miniature gas sensors rely on gas diffusion into the device housing to detect an ambient gas and to infer the ambient gas concentration. However, human skin lipids produce squalene, an oily organic compound that can stick to the housing surface and/or sensor packaging. Squalene reacts strongly with oxidizing gases (e.g., ozone and nitrogen oxides), which could significantly increase the errors of such sensors. Conventional methods may use a physical mesh (e.g., a stainless steel mesh) to prevent accumulation of dust or larger particles. The mesh, however, may not be effective toward oily organic compounds such as skin oil. Another mitigation scheme adopts active air flow (e.g., by using a pump or a fan) to compensate for analyte depletion. This scheme may not be ideal for mobile devices, given the size, power and noise impacts. Thus, methods suitable for mobile electronic devices are needed to remove organic contaminants and to clean the device housing and sensor packaging in order to ensure accuracy of the environmental sensors.

Photo-oxidation removal of organic contamination for environmental sensor integration


A non-aqueous liquid heavy duty laundry detergent composition comprising a suspension of builder salt in liquid nonionic surfactant in which the stability of the composition is improved by the addition of small amounts of organophilic modified clay. Stability is further enhanced by grinding the solid particulate matter, including builder salt, bleach and other minor ingredients to a particle size below about 15 microns. The preferred organophilic modified clay is a water-swellable smectite clay in which the metal cations are totally or partially exchanged with a mono- or di-long chain quaternary ammonium compound.

1. Field of Invention
This invention relates to non-aqueous liquid fabric treating compositions. More particularly, this invention relates to thickened non-aqueous liquid laundry detergent compositions which are stable against phase separation and gelation and are easily pourable and to the use of these compositions for cleaning soiled fabrics, and dispensers therefor.
2. Discussion of Prior Art
Liquid nonaqueous heavy duty laundry detergent compositions are well known in the art. For instance, compositions of that type may comprise a liquid nonionic surfactant in which are dispersed particles of a builder, as shown for instance in U.S. Pat. Nos. 4,316,812; 3,630,929; 4,264,466; and 4,661,280.
Liquid detergents are often considered to be more convenient to employ than dry powered or particulate products and, therefore, have found substantial favor with consumers. They are readily measurable, speedily dissolved in the wash water, capable of being easily applied in concentrated solutions or dispersions to soiled areas on garments to be laundered and are non-dusting, and they usually occupy less storage space. Additionally, the liquid detergents may have incorporated in their formulations materials which could not stand drying operations without deterioration, which materials are often desirably employed in the manufacture of particular detergent products. Although they are possessed of many advantages over unitary or particulate solid products, liquid detergents often have certain inherent disadvantages too, which have to be overcome to produce acceptable commercial detergent products. Thus, some such products separate out on storage and others separate out on cooling and are not readily redispersed In some cases the product viscosity changes and it becomes either too thick to pour or so thin as to appear watery. Some clear products become cloudy and other gel on standing.
The present inventors have been extensively involved as part of an overall corporate research effort in studying the rheological behavior of nonionic liquid surfactant systems with and without particulate matter suspended therein. Of particular interest has been non-aqueous built laundry liquid detergent compositions and the problems of phase separation and settling of the suspended builder and other laundry additives. These considerations have an impact on, for example, product pourability, dispersibility and stability.
The rheological behavior of the non-aqueous built liquid laundry detergents can be analogized to the rheological behavior of paints in which the suspended builder particles correspond to the inorganic pigment and the non-ionic liquid surfactant corresponds to the non-aqueous paint vehicle.
It is known that one of the major problems with built liquid laundry detergents is their physical stability. This problem stems from the fact that the density of the solid suspended particles is higher than the density of the liquid matrix. Therefore, the particles tend to sediment according to Stoke's law. Two basic solutions exist to solve the sedimentation problem: liquid matrix viscosity and reducing solid particle size.
For instance, it is known that such suspensions can be stabilized against settling by adding inorganic or organic thickening agents or dispersants, such as, for example, very high surface area inorganic materials, e.g. finely divided silica, clays, etc., organic thickeners, such as the cellulose ethers, acrylic and acrylamide polymers, polyelectrolytes, etc. However, such increases in suspension viscosity are naturally limited by the requirement that the liquid suspension be readily pourable and flowable, even at low temperature. Furthermore, these additives do not contribute to the cleaning performance of the formulation. U.S. Pat. No. 4,661,280 to T. Ouhadi, et al. discloses the use of aluminum stearate for increasing stability of suspensions of builder salts in liquid nonionic surfactant. The addition of small amounts of aluminum stearate increases yield stress without increasing plastic viscosity.
It has long been known that aqueous swelling colloidal clays, such as bentonite and montmorillonite clays, can be modified by exchange of the metallic cation groups with organic groups, thereby changing the hydrophilic clays to organophilic clays. The use o f such organophilic clays as gel-forming clays has been described in U.S. Pat. No. 2,531,427 to E. A. Hauser. Improvements and modifications of the organophilic gel-forming clays are described, for example, in the following U.S. Pat. Nos.: 2,966,506 - Jordan; 4,105,578 - Finlayson, et al.; 4,208,218 - Finlayson; 4,287,086 - Finlayson; 4,434,075 - Mardis, et al.; 4,434,076 - Mardis, et al.; all assigned to NL Industries, Inc., formerly National Lead Company. According to these NL patents, these organophilic clay gellants are useful in lubricating greases, oil based muds, oil base packer fluids, paints, paint-varnish-lacquer removers, adhesives, sealants, inks, polyester gel coats and the like. However, use as a stabilizer in a non-aqueous liquid detergent composition for laundering fabrics has not been suggested.
On the other hand, the use of clays in combination with quaternary ammonium compounds (often referred to as "QA" compounds) to impart fabric softening benefits to laundering compositions has also been described. For instance, mention can be made of the British Patent Application GB 2,141,152 A, published Dec. 12, 1984, to P. Ramachandran, and the many patents referred to therein of fabric softening compositions based on organophilic QA clays.
According to the aforementioned U.S. Pat. No. 4,264,466 to Carleton, et al., the physical stability of a dispersion of particulate material, such as detergent builders, in a non-aqueous liquid phase is improved by using as a primary suspending agent an impalpable chain structure type clay, including sepiolite, attapulgite, and palygorskite clays. The patentees state and the comparative examples in this patent show that other types of clays, such as montmorillonite clay, e.g. Bentolite L, hectorite clay (e.g. Veegum T) and kaolinite clay (e.g. Hydrite PX), even when used in conjunction with an auxiliary suspension aid, including cationic surfactants, inclusive of QA compounds, are only poor suspending agents. Carleton, et al. also refer to use of other clays as suspension aids and mention, as examples, U.S. Pat. Nos. 4,069,034; 4,005,027 (both aqueous systems); 4,166,039; 3,259,574; 3,557,037; 3,549,542; and U.K. Patent Application 2,017,072.
Grinding to reduce the particle size provides the following advantages:
1. The particle specific surface area is increased, and, therefore, particle wetting by the non-aqueous vehicle (liquid non-ionic) is proportionately improved.
2. The average distance between pigment particles is reduced with a proportionate increase in particle-to-particle interaction. Each of these effects contributes to increase the rest-gel strength and the suspension yield stress while at the same time, grinding significantly reduces plastic viscosity.
The above-mentioned U.S. Pat. No. 4,316,812 discloses the benefits of grinding solid particles, e.g. builder and bleach, to an average particle diameter of less than 10 microns. However, it has been found that merely grinding to such small particle sizes does not, by itself, impart sufficient long term stability against phase separation.
Therefore, still further improvements are desired in the stability of non-aqueous liquid fabric treating compositions.
Accordingly, it is an object of the invention to provide liquid fabric treating compositions which are suspensions of insoluble fabric-treating particles in a non-aqueous liquid and which are storage stable, easily pourable and dispersible in cold, warm or hot water.
Another object of this invention is to formulate highly built heavy duty non-aqueous liquid nonionic surfactant laundry detergent compositions which resist settling of the suspended solid particles or separation of the liquid phase.
Still another object of this invention is to provide a disposable single use package-dispenser for the liquid laundry detergent composition.
A specific object of this invention is to provide non-gelling, stable suspensions of heavy duty built non-aqueous liquid nonionic laundry detergent composition which includes a non-aqueous liquid composed of a nonionic surfactant, fabrictreating solid particles suspended in the non-aqueous liquid, and an amount up to about 1% by weight of an organophilic water-swellable smectite clay modified with a cationic nitrogen containing compound including at least on long chain hydrocarbon having from about 8 to about 22 carbon atoms to form an elastic network or structure throughout the suspension to increase the yield stress of the composition to thereby increase its stability, i.e. prevent settling of builder particles, etc., preferably while reducing or at least without significantly increasing, the plastic viscosity (viscosity under shear conditions) of the composition.
These and other objects of the invention which will become more apparent from the following detailed description of preferred embodiments have been accomplished based on the inventors' discovery that by adding to the non-aqueous liquid suspension a small amount of an organophlic modified clay, an elastic network structure is provided and enhances the cohesiveness of the suspension which, together with the natural tendency of the finely divided solid suspended particles to flocculate, is effective to inhibit settling of the suspended solid fabric treating particles, e.g. detergent builder, bleaching agent, antistatic agent, etc.
Accordingly, in one aspect the present invention provides a liquid heavy duty laundry composition composed of a suspension of a detergent builder salt in a liquid nonionic surfactant wherein the composition includes an amount of organophilic clay to increase the stability of the suspension.
According to another aspect, the invention provides a method for cleaning soiled fabrics by contacting the soiled fabrics with the non-aqueous liquid laundry detergent composition as described above.
According to still another aspect, the invention provides in one embodiment a single use disposable package for dispensing the thickened non-aqueous suspension and in another embodiment a doserette is used to dispense the laundry detergent composition product.
The liquid phase of the non-aqueous liquid detergent composition of this invention is comprised predominantly or totally of liquid nonionic synthetic organic detergent. A portion of the liquid phase may be composed, however, of organic solvents which may enter the composition as solvent vehicles or carriers for one or more of the solid particulate ingredients, such as in enzyme slurries, perfumes, and the like. Also, as will be described in detail below, organic solvents, such as alcohols and ethers, may be added as viscosity control and anti-gelling agents.
The nonionic synthetic organic detergents employed in the practice of the invention may be any of a wide variety of such compounds, which are well known and, for example, are described at length in the text Surface Active Agents, Vol. II, by Schwartz, Perry and Berch, published in 1958 by Interscience Publishers, and in McCutcheon's Detergents and Emulsifiers, 1969 Annual, the relevant disclosures of which are hereby incorporated by reference. Usually, the nonionic detergents are poly-lower alkoxylated lipophiles wherein the desired hydrophile-lipophile balance is obtained from addition of a hydrophilic poly-lower alkoxy group to a lipophilic moiety. A preferred class of the nonionic detergent employed is the poly-lower alkoxylated higher alkanol wherein the alkanol is of 10 to 22 carbon atoms and wherein the number of mols of lower alkylene oxide (of 2 or 3 carbon atoms) is from 3 to 20. Of such materials it is preferred to employ those wherein the higher alkanol is a higher fatty alcohol of 10 to 11 or 12 to 15 carbon atoms and which contain from 5 to 18, preferably 6 to 14 lower alkoxy groups per mol. The lower alkoxy is often just ethoxy but in some instances, it may be desirably mixed with propoxy, the latter, if present, often being a minor (less than 50%) proportion. Exemplary of such compounds are those wherein the alkanol is of 12 to 15 carbon atoms and which contain about 7 ethylene oxide groups per mol, e.g. Neodol 25-7 and Neodol 23-6.5, which products are made by Shell Chemical Company, Inc. The former is a condensation product of a mixture of higher fatty alcohols averaging about 12 to 15 carbon atoms, with about 7 mols of ethylene oxide and the latter is a corresponding mixture wherein the carbon atom content of the higher fatty alcohol is 12 to 13 and the number of ethylene oxide groups present averages about 6.5. The higher alcohols are primary alkanols. Other examples of such detergents include Tergitol 15-S-7 and Tergitol 15-S-9, both of which are linear secondary alcohol ethoxylates made by Union Carbide Corp. The former is mixed ethoxylation product of 11 to 15 carbon atoms linear secondary alkanol with seven mols of ethylene oxide and the latter is a similar product but with nine mols of ethylene oxide being reacted.
Also useful in the present compositions as a component of the nonionic detergent are higher molecular weight nonionics, such as Neodol 45-11, which are similar ethylene oxide condensation products of higher fatty alcohols, with the higher fatty alcohol being of 14 to 15 carbon atoms and the number of ethylene oxide groups per mol being about 11. Such products are also made by Shell Chemical Company. Other useful nonionics are represented by the commercially well known class of nonionics which are the reaction product of a higher linear alcohol and a mixture of ethylene and propylene oxides, containing a mixed chain of ethylene oxide and propylene oxide, terminated by a hydroxyl group. Examples include the nonionics sold under the Plurafac trademark of BASF, such as Plurafac RA30, Plurafac RA40 (a C.sub.13 -C.sub.15 fatty alcohol condensed with 7 moles propylene oxide and 4 moles ethylene oxide), Plurafac D25 (C.sub.13 -C.sub.15 fatty alcohol condensed with 5 moles propylene oxide an 10 moles ethylene oxide), Plurafac B26, and Plurafac RA50 (a mixture of equal parts Plurafac D25 and Plurafac RA40).
Generally, the mixed ethylene oxide-propylene oxide fatty alcohol condensation products represented by the general formula EQU RO(C.sub.3 H.sub.6 O).sub.p (C.sub.2 H.sub.4 O).sub.q H,
wherein R is a straight or branched, primary or secondary aliphatic hydrocarbon, preferably alkyl or alkenyl, especially preferably alkyl, of from 6 to 20, preferably 10 to 18, especially preferably 12 to 18 carbon atoms, p is a number of from 2 to 8, preferably 3 to 6, and q is a number of from 2 to 12, preferably 4 to 10, can be advantageously used where low foaming characteristics are desired. In addition, these surfactants have the advantage of low gelling temperatures.
Another group of liquid nonionics are available from Shell Chemical Company, Inc. under the Dobanol trademark: Dobanol 91-5 is an ethoxylated C.sub.9 -C.sub.11 fatty alcohol with an average of 5 moles ethylene oxide; Dobanol 25-7 is an ethoxylated C.sub.12 -C.sub.15 fatty alcohol with an average of 7 moles ethylene oxide; etc.
In the preferred poly-lower alkoxylated higher alkanols, to obtain the best balance of hydrophilic and lipophilic moieties the number of lower alkoxies will usually be from 40% to 100% of the number of carbon atoms in the higher alcohol, such as 40 to 60% thereof and the nonionic detergent will often contain at least 50% of such preferred poly-lower alkoxy higher alkanol.
Higher molecular weight alkanols and various other normally solid nonionic detergents and surface active agents may be contributory to gelation of the liquid detergent and consequently, will preferably be omitted or limited in quantity in the present compositions, although minor proportions thereof may be employed for their cleaning properties, etc. With respect to both preferred and less preferred nonionic detergents the alkyl groups present therein are generally linear although branching may be tolerated, such as at a carbon next to or two carbons removed from the terminal carbon of the straight chain and away from the alkoxy chain, if such branched alkyl is not more than three carbons in length. Normally, the proportion of carbon atoms in such a branched configuration will be minor rarely exceeding 20% of the total carbon atom content of the alkyl. Similarly, although linear alkyls which are terminally joined to the alkylene oxide chains are highly preferred and are considered to result in the best combination of detergency, biodegradability and non-gelling characteristics, medial or secondary joinder to the alkylene oxide in the chain may occur. It is usually in only a minor proportion of such alkyls, generally less than 20% but, as is the case of the mentioned Terigtols, may be greater. Also, when propylene oxide is present in the lower alkylene oxide chain, it will usually be less than 20% thereof and preferably less than 10% thereof.
When greater proportions of non-terminally alkoxylated alkanols, propylene oxide-containing poly-lower alkoxylated alkanols and less hydrophile-lipophile balanced nonionic detergent than mentioned above are employed and when other nonionic detergents are used instead of the preferred nonionics recited herein, the product resulting may not have as good detergency, stability, viscosity and non-gelling properties as the preferred compositions but use of viscosity and gel controlling compounds can also improve the properties of the detergents based on such nonionics. In some cases, as when a higher molecular weight polylower alkoxylated higher alkanol is employed, often for its detergency, the proportion thereof will be regulated or limited in accordance with the results of routine experiments, to obtain the desired detergency and still have the product non-gelling and of desired viscosity. Also, it has been found that it is only rarely necessary to utilize the higher molecular weight nonionics for their detergent properties since the preferred nonionics described herein are excellent detergents and additionally, permit the attainment of the desired viscosity in the liquid detergent without gelation at low temperatures. Mixtures of two or more of these liquid nonionics can also be used and in some cases advantages can be obtained by the use of such mixtures.
In view of their low gelling temperatures and low pour points, another preferred class nonionic surfactants includes the C12-C13 secondary fatty alcohols with relatively narrow contents of ethylene oxide in the range of from about 7 to 9 moles, especially about 8 moles ethylene oxide per molecule and the C9 to C11, especially C10 fatty alcohols ethoxylated with about 6 moles ethylene oxide.
Furthermore, in the compositions of this invention, it may be advantageous to include an organic solvent or diluent which can function as a viscosity control and gel-inhibiting agent for the liquid nonionic surface active agents. Lower (C.sub.1 -C.sub.6) aliphatic alcohols and glycols, such as ethanol, isopropanol, ethylene glycol, hexylene glycol and the like have been used for this purpose. Polyethylene glycols, such as PEG 400, are also useful diluents. Alkylene glycol ethers, such as the compounds sold under the trademarks, Carbopol and Carbitol which have relatively short hydrocarbon chain lengths (C2-C8) and a low content of ethylene oxide (about 2 to 6 EO units per molecule) are especially useful viscosity control and anti-gelling solvents in the compositions of this invention. The use of the alkylene glycol ethers is disclosed in the commonly assigned copending application Serial No. 687,815, filed Dec. 31, 1984, to T. Ouhadi, et al. Suitable glycol ethers can be represented by the following general formula EQU RO(CH.sub.2 CH.sub.2 O).sub.n H
where R is a C.sub.2 -C.sub.8, preferably C.sub.2 -C.sub.5, alkyl group, and n is a number of from about 1 to 6, preferably 1 to 4, on average.
Specific examples of suitable solvents include ethylene glycol monoethyl ether (C.sub.2 H.sub.5 --O--CH.sub.2 CH.sub.2 OH), diethylene glycol monobutyl ether (C.sub.4 H.sub.9 --O--(CH.sub.2 CH.sub.2 O).sub.2 H), tetraethylene glycol monooctyl ether (C.sub.8 H.sub.17 --O--(CH.sub.2 CH.sub.2 O).sub.4 H), etc. Diethylene glycol monobutyl ether is especially preferred.
The amount of the nonionic surfactant is generally within the range of from about 20 to about 70%, such as about 30 to 60 for example 35% or 40% by weight of the composition. The amount of solvent or diluent when present is usually up to 20%, preferably up to 15%, for example, 0.5 to 15%, preferably 5.0 to 12%. The weight ratio of nonionic surfactant to alkylene glycol ether as the viscosity control and anti-gelling agent, when the latter is present, as in the preferred embodiment of the invention is in the range of from about 100:1 to 1:1, preferably from about 50:1 to about 2:1, such as 1:1, 8:1, 6:1 or 4:1.
The invention detergent compositions also include as an essential ingredient water soluble and/or water dispersible detergent builder salts. Typical suitable builders include, for example, those disclosed in the aforementioned U.S. Pat. Nos. 4,316,812, 4,264,466, 3,630,929, and many others. Water-soluble inorganic alkaline builder salts which can be used alone with the detergent compound or in admixture with other builders are alkali metal carbonate, borates, phosphates, polyphosphates, bicarbonates, and silicates. (Ammonium or substituted ammonium salts can also be used.) Specific examples of such salts are sodium tripolyphosphate, sodium carbonate, sodium tetraborate, sodium pyrophosphate, potassium pyrophosphate, sodium bicarbonate, potassium tripolyphosphate, sodium hexametaphosphate, sodium sesquicarbonate, sodium mono and diorthophosphate, and potassium bicarbonate, sodium tripolyphosphate (TPP) is especially preferred where phosphate containing ingredients are not prohibited due to environmental concerns. The alkali metal silicates are useful builder salts which also function to make the composition anticorrosive to washing machine parts. Sodium silicates of Na.sub.2 O/SiO.sub.2 ratios of from 1.6/1 to 1/3.2, especially about 1/2 to 1/2.8 are preferred. Potassium silicates of the same ratios can also be used.
Another class of builders highly useful herein are the water-insoluble aluminosilicates, both of the crystalline and amorphous type. Various crystalline zeolites (i.e. aluminosilicates) are described in British Patent 1,504,168, U.S. Pat. No. 4,409,136 and Canadian Patents 1,072,835 and 1,087,477, all of which are hereby incorporated by reference for such descriptions. An example of amorphous zeolites useful herein can be found in Belgium Patent 835,351 and this patent too is incorporated herein by reference. The zeolites generally have the formula EQU (M.sub.2 O).sub.x .multidot.(Al.sub.2 O.sub.3).sub.y .multidot.(SiO.sub.2).sub.z .multidot.WH.sub.2 O
wherein x is 1, y is from 0.8 to 1.2 and preferably 1, z is from 1.5 to 3.5 or higher and preferably 2 to 3 and w is from 0 to 9, preferably 2.5 to 6 and M is preferably sodium. A typical zeolite is type A or similar structure, with type 4A particularly preferred. The preferred aluminosilicates have calcium ion exchange capacities of about 200 milliequivalents per gram or greater, e.g. 400 meq/0 g.
Examples of organic alkaline sequestrant builder salts which can be used alone with the detergent or in admixture with other organic and inorganic builders are alkali metal, ammonium or substituted ammonium, aminopolycarboxylates, e.g. sodium and potassium ethylene diaminetetraacetate (EDTA), sodium and potassium nitrilotriacetates (NTA) and triethanolammonium N-(2-hydroxyethyl)nitrilodiacetates. Mixed salts of these polycarboxylates are also suitable.
Other suitable builders of the organic type include carboxymethylsuccinats, tartronates and glycollates and the polyacetal carboxylates. The polyacetal carboxylates and their use in detergent compositions are described in U.S. Pat. Nos. 4,144,226; 4,315,092 and 4,146,495. Other patents on similar builders include U.S. Pat. Nos. 4,141,676; 4,169,934; 4,201,858; 4,204,852; 4,224,420; 4,225,685; 4,226,960; 4,233,422; 4,233,423; 4,302,564 and 4,303,777. Also relevant are European Patent Application Nos. 0015024, 0021491 and 0063399.
The proportion of the suspended detergent builder, based on the total composition, is usually in the range of from about 10 to 60 weight percent, such as about 20 to 50 weight percent, for example about 25 to 40% by weight of the composition.
According to this invention the physical stability of the suspension of the detergent builder compound or compounds and any other suspended additive, such as bleaching agent, etc., in the liquid vehicle is drastically improved by the presence of a stabilizing agent which, according to this invention, is an elastic network forming organophilic modified clay.
The organophilic modified clay can be based on any swelling clay modified to exhibit high gelling efficiency in the organic liquid vehicle. As examples of such swelling clay materials which can be used (after appropriate modification as described below) mention can be made of the smectite clays especially the bentonites, e.g. sodium and lithium bentonites; montmorillonites, e.g. sodium and calcium montmorillonites; saponites, e.g. sodium saponites; and hectorites, e.g. sodium hectorites. Other representative clays include beidellite and stevensite.
The aforementioned smectite-type clays are three-layer clays characterized by the ability of the layered structure to increase its volume several-fold by swelling or expanding when in the presence of water to form a thixotropic gelatinous substance. There are two main classes of smectite-type clays: in the first class, aluminum oxide is present in the silicate crystal lattice; in the second class, magnesium oxide is present in the silicate crystal lattice. Atom substitution by iron, magnesium, sodium, potassium, calcium and the like can occur within the crystal lattice of the smectite clays. It is customary to distinguish between clays on the basis of their predominant cation. For example, a sodium clay is one in which the cation is predominantly sodium. Aluminum silicates wherein sodium is the predominant cation are preferred, such as, for example, bentonite clays. Among the bentonite clays, those from Wyoming (generally referred to as western or Wyoming bentonite) are especially preferred.
Preferred swelling bentonites are sold under the trademark Mineral Colloid, as industrial bentonites. by Benton Clay Company, an affiliate of Georgia Kaolin Co. These materials which are the same as those formerly sold under the trademark THIXO-JEL, are selectively mined and beneficiated bentonites, and those considered to be most useful are available as Mineral Colloid No's. 101, etc. corresponding to THIXO-JELs No's 1, 2, 3 and 4. Such materials have pH's (6% concentration in water) in the range of 8 to 9.4, maximum free moisture contents of about 8% and specific gravities of about 2.6, and for the pulverized grade at least about 85% (and preferable 100%) passes through a 200 mesh U.S. Sieve Series sieve. More preferably, the bentonite is one wherein essentially all the particles (i.e. at least 90% thereof, preferably over 95%) pass through a No. 325 sieve and most preferably all the particles pass through such a sieve. The swelling capacity of the bentonites in water is usually in the range of 2 to 15 ml/gram, and its viscosity, at a 6% concentration in water, is usually from about 8 to 30 centipoises.
Instead of utilizing the THIXO-JEL or Mineral Colloid bentonites one may employ products, such as that sold by American Colloid Company, Industrial Division, as General Purpose Bentonite Powder, 325 mesh, which has a minimum of 95% thereof finer than 325 mesh or 44 microns in diameter (wet particle size) and a minimum of 96% finer than 200 mesh or 74 microns diameter (dry particle size). Such a hydrous aluminum silicate is comprised principally of montmorillonite (90% minimum), with smaller proportions of feldspar, biotite and selenite. A typical analysis on an "anhydrous" basis, is 63.0% silica, 21.5% alumina, 3.3% of ferric iron (as Fe.sub.2 O.sub.3), 0.4% of ferrous iron (as FeO), 2.7% of magnesium (as MgO), 2.6% of sodium and potassium (as Na.sub.2 O). 0.7% of calcium (as CoO), 5.6% of crystal water (as H.sub.2 O) and 0.7% of trace elements.
Although the western bentonites are preferred it is also possible to utilize other bentonites, such as those which may be made by treating Italian or similar bentonites containing relatively small proportions of exchangeable monovalent metals (sodium and potassium) with alkaline materials, such as sodium carbonate, to increase the cation exchange capacities of such products. It is considered that the Na.sub.2 O content of the bentonite should be at least about 0.5%, preferably at least 1% and more preferably at least 2% so that the clay will be satisfactory swelling. Preferred swelling bentonites of the types described above are sold under the trade names Laviosa and Winkelmann, e.g. Laviosa AGB and Winkelmann G-13. Other examples include Veegum F and Laponite SP, both sodium hectorites, Gelwhite L, a calcium montmorillonite, Gelwhite GP, a sodium montmorillonite, Barasym LIH 200, a lithium hectorite.
The smectite clay materials as described above are hydrophilic in nature. i.e. they display swelling characteristics in aqueous media. Conversely, they are organophobic in nature and do note swell in nonaqueous or predominantly non-aqueous systems.
According to this invention, the organophobic nature of the smectite clay materials is converted to an organophilic nature. This can be accomplished be exchanging the metal cation, e.g. Na, K, Li, Ca, etc. of the clay, with an organic cation, at least on the surface of the clay particles. This can be accomplished, for example, by admixing the clay, organic cation and water, together, preferably at a temperature within the range of 20.degree. C. to 100.degree. C., for a period of time sufficient for the organic cation to intercalate with the clay particles at least on the surface, followed by filtering, washing, drying and grinding. For further details reference can be made to any of the aforementioned U.S. Pat. Nos. 2,531,427, 2,966,506, 4,105,578, 4,208,218, 4,287,086, 4,424,075 and 4,434,076, the disclosures of which are incorporated herein in their entireties by reference thereto.
The organic cationic material is preferably a quaternary ammonium compound, particularly one having surfactant properties, indicative of at least one long chain hydrocarbon group (e.g. from about 8 to about 22 carbon atoms), although surfactant properties or other fabric beneficial properties are not required, nor is it essential that the cationic modifier itself be useful as a suspension agent. However, any of the cationic surfactant compounds disclosed as useful auxiliary suspension aids in the aforementioned U.S. Pat. No. 4,264,466, at columns 23-29, the disclosure of which is incorporated herein in its entirety, can be used for modifying the smectite clay material to render the latter organophilic. The organic cationic nitrogen compounds described in the aforementioned U.S. Pat. No. 2,531,427 to Hauser, or these mentioned in any of the NL Industries U.S. Pat. Nos. 2,966,506; 4,105,578, and so on, the disclosures of which are incorporated herein be reference, can also be favorably used.
The preferred modifiers are the quaternary ammonium compounds of formula EQU [R.sub.1 R.sub.2 R.sub.3 R.sub.4 N].sup.+ X.sup.--
wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4, are each, independently, hydrogen, or a hydrophobic organic alkyl, aryl, aralkyl, alkaryl or alkenyl radical containing from 1 to 30 carbon atoms, preferably 1 to 22 carbon atoms, at least two R groups preferably having from 1 to 6 carbon atoms and at least one R group, preferably at most two R groups, having from 8 to 22 carbon atoms; and X is an anion, which may be inorganic, such as, halide, e.g. chloride or bromide, sulfate, phosphate, hydroxide, or nitrate, or organic, such as, methylsulfate, ethylsulfate, or fatty acid, e.g. acetate, propionate, laurate, myristate, palmitate, oleate or stearate.
Examples of preferred organophilic modifiers are the mono-and di-long chain (e.g. C.sub.8 to C.sub.18, especially C.sub.10 to C.sub.18) alkyl quaternary compounds. Representative examples of the mono-long chain quaternary ammonium surfactants include stearyl trimethyl ammonium chloride, tallow trimethyl ammonium chloride, benzyl stearyl dimethyl ammonium chloride, benzyl hydrogenated tallow dimethyl ammonium chloride, benzyl cetyl dimethyl ammonium chloride and the corresponding bromides, iodides, sulfates, methosulates, acetates, and other anions previously mentioned. Typical representative examples of the di-long chain quaternary ammonium compounds include dimethyl distearyl ammonium chloride, dimethyl dicetyl ammonium chloride, dimethyl stearyl cetyl ammonium chloride, dimethyl ditallow ammonium chloride, dimethyl myristyl cetyl ammonium chloride, and the corresponding bromides, iodides, sulfates, methosulfates, acetates and other anions previously mentioned. Other representative compounds include octadecyl ammonium chloride, hexadecyl ammonium acatete, and so on.
In addition to the quaternary ammonium (QA) compounds, other quaternizable nitrogen containing organic cations can also be used to form organophilic clay particles. For instance mention can be made of imidazolinium compounds such as, for example, 1-(2-hydroxyethyl)-2-dodecyl-1-benzyl-2 imidazolinium chloride, and heterocyclic nitrogen ring containing compounds, such as long chain hydrocarbon substituted pyrrolidones, pyridenes, morpholines, and the like, such as N,N-octadecylmorpholinium chloride.
The amount of organic cation substitution need only be that amount sufficient to impart to the clay the requisite organophilic property to provide the enhanced stabilizing characteristic desired. Generally, depending on the nature of the organic substituent this amount can range from about 10 to 100%, preferably 20 to 100%, such as 30%, 40%, 50% or 60%, of the available base exchange capacity of the clay material. Usually, and preferably, at least sufficient of the organic compound is used to cover or coat the surface of the clay particles.
Suitable organophilic clays which can be used in this invention are commercially available, for example, the products sold under the Bentone trademark of NL Industries, New York, N.Y., such as Bentone 27, which is a hectorite clay (magnesium montmorrilonite) modified with benzyl dimethyl hydrogenated tallow ammonium chloride, and Bentone 38, which is a hectorite clay, modified with dimethyl dioctadecyl ammonium chloride. Other sources of organophilic clays include, for example, Sud-Chemie, Munich Germany; Laviosa, Livorno, Italy; Laporte, France; and Perchem, United Kingdom.
The organophlic clays are used in only minor amount, generally less than 1.0% by weight, preferably less than 0.7% by weight, based on the total composition. Usually, amounts of at least about 0.1 weight percent, preferably 0.2 weight percent, such as 0.25%, 0.3%, 0.35% or 0.4%, will enable production of stable, thixotropic non-aqueous liquid suspensions of finely divided detergent builder or other water soluble or dispersible fabric treating agent.
The organophilic modified clay can be incorporated into the non-aqueous liquid dispersion of the suspended particulate ingredients either directly as a powder or after first being predispersed in a portion of the liquid vehicle of the suspension, e.g. the liquid nonionic surfactant, the latter method being preferred. Furthermore, whether added to the suspension directly as a powder or pregelled in a portion of the liquid vehicle, the organophilic clay may be added to the suspension before or after the suspension is ground to the required average particle size of no more than 15 microns, preferably no more than 10, especially from 1 to 10 microns, most preferably from 4 to 8 microns.
In a preferred embodiment the organophilic clay is first predispersed either in part of the liquid nonionic surfactant forming the principal liquid vehicle or in a different nonionic surfactant or in a solvent or diluent as previously described, or in any suitable mixture of surfactant(s), and/or solvent(s), and/or diluent(s). The predispersed clay suspension, if necessary, can be subjected to grinding in a high shear grinder, to form an organophilic clay pregel. Separately, the remaining solid particulate matter is suspended in the liquid nonionic surfactant and optional diluent/solvent, and is also subjected to grinding. The clay pregel and the particulate matter suspension can be ground to the final desired average particle size before they are mixed with each other, or the pregel and suspension can be mixed and then subjected to further grinding. In the latter case, the suspended particulate matter can further contribute to the attrition of the organophilic clay particles.
Since the compositions of this invention are generally highly concentrated, and, therefore, may be used at relatively low dosages, it is often desirable to supplement any phosphate builder (such as sodium tripolyphosphate) with an auxiliary builder such as a polymeric carboxylic acid having high calcium binding capacity to inhibit incrustation which could otherwise be caused by formation of an insoluble calcium phosphate. Such auxiliary builders are also well known in the art. For example, mention can be made of Sokolan CP5 which is a copolymer of about equal moles of methacrylic acid and maleic anhydride, completely neutralized to form the sodium salt thereof. The amount of the auxiliary builder is generally up to about 6 weight percent, preferably 1/4 to 4%, such as 1%, 2% or 3%, based on the total weight of the composition. Of course, the present compositions, where required by environmental constraints, can be prepared without any phosphate builder.
In addition to the detergent builders, various other detergent additives or adjuvants may be present in the detergent product to give it additional desired properties, either of functional or aesthetic nature. Thus, there may be included in the formulation, minor amounts of soil suspending or anti-redeposition agents, e.g. polyvinyl alcohol, fatty amides, sodium carboxymethyl cellulose, hydroxy-propyl methyl cellulose, usually in amounts up to 10 weight percent, for example 0.1 to 10%, preferably 1 to 5%; optical brighteners, e.g. cotton, polyamide and polyester brighteners, for example, stilbene, triazole and benzidine sulfone compositions, especially sulfonated substituted triazinyl stilbene, sulfonated naphthotriazole stilbene, benzidene sulfone, etc., most preferred are stilbene and triazole combinations. Typically, amount of the optical brightener up to about 2 weight percent, preferably up to 1 weight percent, such as 0.1 to 0.8 weight percent, can be used.
Bluing agents such as ultramarine blue; enzymes, preferably proteolytic enzymes, such as subtilisin, bromelin, papain, trypsin and pepsin, as well as amylase type enzymes, lipase type enzymes, and mixtures thereof; bactericides, e.g. tetrachlorosalicyanilide, hexachlorophene; fungicides; dyes; pigments (water dispersible); preservatives; ultraviolet absorbers; anti-yellowing agents, such as sodium carboxymethyl cellulose, complex of C.sub.12 to C.sub.22 alkyl alcohol with C.sub.12 to C.sub.18 alkylsulfate; pH modifiers and pH buffers; color safe bleaches, perfume, and anti-foam agents or suds-suppressors, e.g. silicon compounds can also be used.
The bleaching agents are classified broadly for convenience, as chlorine bleaches and oxygen bleaches. Chlorine bleaches are typified by sodium hypochlorite (NaOCl), potassium dichloroisocyanurate (59% available chlorine), and trichloroisocyanuric acid (95% available chlorine). Oxygen bleaches are preferred and are represented by percompounds which liberate hydrogen peroxide solution. Preferred examples include sodium and potassium perborates, percabonates, and perphosphates, and potassium monopersulfate The perborates, particularly sodium perborate monohydrate, are especially preferred.
The peroxygen compound is preferably used in admixture with an activator therefor. Suitable activators which can lower the effective operating temperature of the peroxide bleaching agent are disclosed, for example, in U.S. Pat. No. 4,264,466 or in column 1 of U.S. Pat. No. 4,430,244, the relevant disclosures of which are incorporated herein be reference. Polyacylated compounds are preferred activators; among these, compounds such as tetraacetyl ethylene diamine ("TAED") and pentaacetyl glucose are particularly preferred.
Other useful activators include, for example, acetylsalicylic acid derivatives, ethylidene benzoate acetate and its salts, ethylidene carboxylate acetate and its salts, alkyl and alkenyl succinic anhydride, tetraacetylglycouril ("TAGU"), and the derivatives of these. Other useful classes of activators are disclosed, for example, in U.S. Pat. Nos. 4,111,826, 4,422,950 and 3,661,789.
The bleach activator usually interacts with the peroxygen compound to form a peroxyacid bleaching agent in the wash water. It is preferred to include a sequestering agent of high complexing power to inhibit any undesired reaction between such peroxyacid and hydrogen peroxide in the wash solution in the presence of metal ions. Preferred sequestering agents are able to form a complex with Cu.sup.2 + ions, such that the stability constant (pK) of the complexation is equal to or greater than 6, at 25.degree. C., in water, of an ionic strength of 0.1 mole/liter, pK being conventionally defined by the formula: pK=-log K where K represents the equilibrium constant. Thus, for example, the pK values for complexation of copper ion with NTA and EDTA at the stated conditions are 12.7 and 18.8, respectively. Suitable sequestering agents include, for example, in addition to those mentioned above, the compounds sold under the Dequest trademark, such as, for example, diethylene triamine pentaacetic acid (DETPA); diethylene triamine pentamethylene phosphonic acid (DTPMP); and ethylene diamine tetramethylene phosphonic acid (EDITEMPA).
In order to avoid loss of peroxide bleaching agent, e.g. sodium perborate, resulting from enzyme-induced decomposition, such as by catalase enzyme, the compositions may additionally include an enzyme inhibitor compound, i.e. a compound capable of inhibiting enzyme-induced decomposition of the peroxide bleaching agent. Suitable inhibitor compounds are disclosed in U.S. Pat. No. 3,606,990, the relevant disclosure of which is incorporated herein by reference.
Of special interest as the inhibitor compound, mention can be made of hydroxylamine sulfate and other water-soluble hydroxylamine salts. In the preferred nonaqueous compositions of this invention, suitable amounts of the hydroxylamine salt inhibitors can be as low as about 0.01 to 0.4%. Generally, however, suitable amounts of enzyme inhibitors are up to about 15%, for example, 0.1 to 10%, by weight of the composition.
The composition may also contain an inorganic insoluble thickening agent or dispersant of very high surface area such as finely divided silica of extremely fine particle size (e.g. of 5-100 millimicrons diameters such as sold under the name Aerosil) or the other highly voluminous inorganic carrier materials disclosed in U.S. pat. No. 3,630,929. It is preferable, however, that compositions which form peroxyacids in the wash bath (e.g. compositions containing peroxygen compound and activator therefor) be substantially free of such compounds and of other silicates; it has been found, for instance, that silica and silicates promote the undesired decomposition of the peroxyacid.
Although not required to achieve acceptable product stability, it is also within the scope of this invention to include other suspension stabilizers, rheological additives, and antigelling agents. For example, the aluminum salts of higher fatty acids, especially aluminum stearate, as disclosed in U.S. Pat. No. 4,661,280, the disclosure of which is incorporated herein by reference, can be added to the composition, for example, in amount of 0 to 3% by weight, preferably 0 to 1% by weight.
Another potentially useful stabilizer for use in conjunction with the organophilic clay, is an acidic organic phosphorus compound having an acidic-POH group, as disclosed in the commonly assigned copending application Ser. No. 781,189, filed Sept. 25, 1985, to Brose, et al., the disclosure of which is incorporated herein by reference thereto. The acidic organic phosphorus compound, may be, for instance, a partial ester of phosphoric acid and an alcohol, such as an alkanol having a lipophilic character, having, for instance, more than 5 carbon atoms, e.g. 8 to 20 carbon atoms. A specific example is a partial ester of phosphoric acid and a C.sub.16 to C.sub.18 alkanol. Empiphos 5632 from Marchon is made up of about 35% monoester and 65% diester. When used amounts of the phosphoric acid compound up to about 3%, preferably up to 1%, are sufficient.
As disclosed in copending application Ser. No. 926,851, filed Nov. 3, 1986, to Broze, et al., now U.S. Pat. No. 4,749,512 the disclosure of which is incorporated herein by reference, a nonionic surfactant which has been modified to convert a free hydroxyl group to a moiety having a free carboxyl group, such as a partial ester of a nonionic surfactant and a polycarboxylic acid, can be incorporated into the composition to further improve rheological properties. For instance, amounts of the acid-terminated nonionic surfactant of up to 1 part per part of the nonionic surfactant are sufficient.
Suitable ranges of these optional detergent additives are: enzymes - 0 to 2%, especially 0.1 to 1.3%; corrosion inhibitors - about 0 to 40%, and preferably 5 to 30%; anti-foam agents and suds-suppressors - 0 to 15%, preferably 0 to 5%, for example 0.1 to 3%; thickening agent and dispersants -0 to 15%, for example 0.1 to 10%, preferably 1 to 5%; soil suspending or anti-redeposition agents and anti-yellowing agents - 0 to 10%, preferably 0.5 to 5%; colorants, perfumes, brighteners and bluing agents total weight 0% to about 2% and preferably 0% to about 1%; pH modifiers and pH buffers0 to 5%, preferably 0 to 2%; bleaching agent - 0% to about 40% and preferably 0% to about 25%, for example 2 to 20%; bleach stabilizers and bleach activators 0 to about 15%, preferably 0 to 10%, for example, 0.1 to 8%; enzyme-inhibitors 0 to 15%, for example, 0.01 to 15%, preferably 0.1 to 10%; sequestering agent of high complexing power, in the range of up to about 5%, preferably 1/4 to 3%, such as about 1/2 to 2%. In the selections of the adjuvants, they will be chosen to be compatible with the main constituents of the detergent composition.
In a preferred form of the invention, the mixture of liquid nonionic surfactant and solid ingredients is subjected to grinding, for example, by a sand mill or ball mill. Especially useful are the attrition types of mill, such as those sold by Wiener-Amsterdam or Netzsch-Germany, for example, in which the particle sizes of the solid ingredients are reduced to less than about 15 microns, e.g. to an average particle size of 2 to 10 microns or even lower (e.g. 1 micron). Preferably less than about 10%, especially less than about 5% of all the suspended particles have particles sizes greater than 15 microns, preferably 10 microns. Since the hygroscopicity of the ground clay generally increases as particles size decreaess it is often preferred that the average particle size be at least about 3 microns, especially about 4 microns. Compositions whose dispersed particles are of such small size have improved stability against separation or settling on storage. Other types of grinding mills, such as toothmill, peg mill and the like, may also be used.
In the grinding operation, it is preferred that the proportion of solid ingredients be high enough (e.g. at least about 40%, such as about 50%) that the solid particles are in contact with each other and are not substantially shielded from one another by the nonionic surfactant liquid. Mills which employ grinding balls (ball mills) or similar mobile grinding elements have given very good results. Thus, one may use a laboratory batch attritor having 8 mm diameter steatite grinding balls. For larger scale work a continuously operating mill in which there are 1 mm or 1.5 mm diameter grinding balls working in a very small gap between a stator and a rotor operating at a relatively high speed (e.g. a CoBall mill) may be employed; when using such a mill, it is desirable to pass the blend of nonionic surfactant and solids first through a mill which does not effect such fine grinding (e.g. a colloid mill) to reduce the paricle size to less than 100 microns (e.g., to about 40 microns) prior to the step of grinding to an average particle diameter below about 10 microns in the continuous ball mill.
Alternatively, the powdery solid particles may be finely ground to the desired size before blending with the liquid matrix, for instance, in a jet-mill.
The compositions of this invention are gel-like liquid suspensions, generally exhibiting non-Newtonian flow characteristics, especially thixotrophy, namely reduced viscosity under applied stress or shear, and behave, rheologically, substantially according to the Casson equation. The compositions are characterized by a yield stress between about 2.5 and 45 pascals, more usually between 10 and 35 pascals, such as 15, 20 or 25 pascals. Furthermore, the compositions have plastic viscosities ranging from about 50 to about 500 m Pa.sec (50 to 500 centipoise), usually from about 80 to 300 m Pa.sec, such as 160, 200 or 240 m Pa.sec. However, when shaken or subjected to stress, such as being squeezed through a narrow opening in a squeeze tube bottle, for example, the product is readily flowable. Thus, the compositions of this invention may conveniently be packaged in ordinary vessels, such a glass or plastic, rigid or flexible bottles, jars or other containers, and dispensed therefrom directly into the aqueous wash bath, such as in an automatic washing machine, in usual amounts, such as 1/4 to 11/2 cups, for example, 1/2 cup, per laundry load (of approximately 3 to 15 pounds, for example), for each load of laundry, usually in 8 to 18 gallons of water. The compositions will remain stable (no more than 1 or 2 mm liquid phase separation) when left to stand for periods of 3 months or longer.
In one embodiment of the invention, rather than pouring the thickened composition directly into the aqueous wash bath, the composition is first transferred into a perforated dispenser (referred to as a "doserette"), such as a plastic (water insoluble) ball, having an inner volume preferably just sufficient to hold up to 11/2 cups, or other appropriate amount corresponding to the maximum recommended dosage for a large load of laundry. For this purpose the ball is provided with a closable fill opening through which the composition can be poured and then closed, for example, a screw cap, friction cap or the like. The perforations will be sufficiently small, for example, 1/64-inch to 1/8-inch, preferably 1/64 to 1/16 inch, in diameter, to prevent the thickened composition from freely flowing out of the perforations in the doserette. However, the perforations are sufficiently large to allow the water of the aqueous wash bath to freely flow into the doserette and to sufficiently dilute the thickened suspension so as to allow the composition to be washed out of the doserette into the aqueous wash bath over the first several minutes of the wash cycle, for example, in about 1 to 3 minutes. In this way, the consumer can readily fill the doserette to the appropriate level for the amount and type of laundry being washed and place the filled doserette (after sealing the fill opening) directly into the washing machine with the load of laundry. Preferably, the doserette is formed of sufficiently strong plastic, such as polystyrene, polyethylene, polypropylene, polyvinyl chloride, etc. to be able to withstand repeated usage.
Alternatively, it may be more convenient in certain cases to pre-package the thickened suspensions in premeasured dosage forms for single use in discardable packets or sachets. For instance, it is known to package various laundry products in pouches formed from water soluble materials, such as polyvinyl alcohol, i.e. hydrolyzed polyvinyl acetate, for example, a degree of hydrolysis of at least 60%, such as 80% to 100%, e.g. 85%.
In a preferred embodiment of the invention, a two component disposable sachet dispenser is used. According to this embodiment, the sachet dispenser includes an outer pouch or bag of a water permeable or porous water insoluble film or fabric and an inner pouch or bag of a water soluble film, such as the polyvinyl alcohol mentioned above. The inner bag is filled to the appropriate unit dosage with the thickened fabric treating suspension and is then sealed. The inner packet is then sealed within the outer packet and may be free floating therein, i.e. not attached to the walls of the outer bag, or it may be sealed to one or more edges or walls thereof by any suitable means, such as adhesives, heat sealing, staples, sewing, etc. In use in the aqueous wash bath the water from the bath permeates or flows through the outer bag and contacts the inner bag which then dissolves upon exposure to the water and exposes the thickened suspension to the wash water inside the pouch and allows the fabric treating detergent, detergent builder, and so on, to permeate out of the outer bag to the aqueous wash bath. In this way, the invention composition can be gradually introduced into the wash bath during the wash cycle, preferably over the course of one or more minutes, for example, from 1 to 5 minutes. Although the non-water soluble outer bag can be fabricated from a perforated water insoluble material, e.g. paper, wax paper, viscose, polyolefin film, polyester film, etc. it is preferred to form the outer film from non-woven fabric. Non-woven polyester fabrics of density ranging from about 10 to 40 grams per square meter, preferably 15 to 30 grams per square meter, especially 18 to 24 grams per square meter have proven effective in practice. It has also been found convenient for most product formulations to use from about 50 to 150 grams of the thickened suspension, preferably 60 to 120 grams, such as 80, 90, 100 or 110 grams, per wash, this amount conveniently fitting in a single sachet dispenser, measuring, for example, from about 3 to 4 or more inches per side, such as 3.5 in..times.3.5 in. or 3.75 in..times.3.75 in. or 4 in..times.4 in.
In place of polyvinyl alcohol film or sheet as the water soluble material for forming the water soluble inner bag of the double wall sachet, other water soluble films or sheets can be used. For example, mention may be made of polyethylene oxide, methyl cellulose, gelatine, polysaccharides, and the like.
The use of a double wall sachet wherein the outer wall is formed of a sealed water insoluble permeable material is two-fold. The water insoluble outer bag can protect the water soluble inner bag from exposure to moisture, e.g. humidity, during storage, but being water permeable will allow exposure of the water soluble film and liquid detergent product so that the detergent and fabric treating ingredients can be dispersed to the fabrics during the wash cycle. Furthermore, because the outer bag of the sachet is and remains sealed during the washing, rinsing, and spin-dry operations of the washing machine, any residue of the water soluble inner bag will be retained within the sachet and will not be deposited on the fabric being laundered. For instance, portions of the partially hydrolyzed polyvinyl acetate may be water insoluble and form clumps upon dissolution of the water soluble portions. These clumps will be retained within the water insoluble outer bag. Also, it may in some case be advantageous to render the inner bag partially water insoluble, for example, by a wax coating, to enhance storage stability. This wax coating will also be retained within the permeable but insoluble outer bag of the sachet.
It is understood that the foregoing detailed description is given merely by way of illustration and that variations may be made therein without departing from the spirit of the invention.
It should also be understood that as used in the specification and in the appended claims the term "non-aqueous" means absense of water, however, small amounts of water, for example up to about 5%, preferably up to about 2%, may be tolerated in the compositions, and therefore, "non-aqueous" compositions can include such small amounts of water, whether added directly or as a carrier or solvent for one of the other ingredients in the composition.
The invention will now be described by way of the following non-limiting example in which all proportions and percentages are by weight, unless otherwise indicated. Also, atmospheric pressure is used unless otherwise indicated.

Built thickened stable non-aqueous cleaning composition and method of use, and package therefor